Add the CAOS desktop client

README.md

@@ -60,6 +60,7 @@ No Rust toolchain is needed system-wide; the flake pins it.
 | `rust-toolchain.toml` | Pins the compiler (`stable` + clippy/rustfmt/rust-src) and the static `musl` target |
 | `Cargo.toml` | Workspace root (members + shared release profile) |
 | `crates/caos/` | The `caos` crate: shared `lib.rs` + `caos` and `caos-cli` binaries |
+| `desktop/` | Native Tauri client, kept in its own Cargo workspace so desktop dependencies never enter worker images |
 | `crates/server/` | The `server` crate → `caos-server` |
 | `crates/worker-*/` | The worker crates |
 | `build-builtins.sh` | Bootstraps the seeded core and publishes `refs/caos/seed` |
@@ -87,10 +88,26 @@ the signal to trust before committing.
 > files are included, but new files are not). After adding a new source file,
 > `git add` it before building.
 
+### Desktop client
+
+The desktop client uses the same conversation engine as `caos tui` and is
+scoped to the Git repository it is launched from. Its transcript scrolls
+independently while the composer stays pinned to the bottom of the window.
+
+```bash
+nix run .#caos-desktop
+```
+
+Build it without launching with `nix build .#caos-desktop`. The desktop remains
+a separate Cargo workspace, and bare `nix build` continues to build only the
+CLI and daemon host tools. See [`desktop/README.md`](desktop/README.md) for the
+direct Cargo command, environment overrides, and current CLI-parity scope.
+
 ## Building
 
 ```bash
 nix build .#caos              # ./result/bin/{caos,caos-cli}
+nix build .#caos-desktop      # ./result/bin/caos-desktop
 nix build .#server            # ./result/bin/server
 ```
 

crates/caos/src/bin/tui/app.rs

@@ -5,14 +5,20 @@ use std::sync::mpsc::{self, Receiver, Sender};
 use std::time::{Duration, Instant};
 
 use caos::chat::{
-    archive_user_conversation, compare_and_set_conversation_title, conversation_load,
-    conversation_load_at, conversation_reference, conversation_snapshot, describe_tool_set,
-    first_available_conversation_name, fork_conversation, generate_conversation_title,
-    interrupt_request, invite_user_to_conversation, list_user_conversations,
-    publish_user_conversation, resume_request, run_chat_turn, set_conversation_title,
-    submit_interjection, unarchive_user_conversation, ConversationLoad, ConversationRole,
-    ConversationSnapshot, InviteOutcome, ToolSetDescription, TurnEvent, TurnOptions, TurnOutcome,
-    TurnPhase, UserConversationStatus, UserConversationSummary, WorkspaceDiff, DEFAULT_MODEL,
+    archive_user_conversation, automatic_conversation_title, compare_and_set_conversation_title,
+    conversation_load, conversation_load_at, conversation_reference, conversation_snapshot,
+    describe_tool_set, first_available_conversation_name, fork_conversation, fresh_conversation_id,
+    generate_conversation_title, interrupt_request, invite_user_to_conversation,
+    list_user_conversations, publish_user_conversation, resume_request, run_chat_turn,
+    set_conversation_title, submit_interjection, unarchive_user_conversation, ConversationLoad,
+    ConversationRole, ConversationSnapshot, InviteOutcome, ToolSetDescription, TurnEvent,
+    TurnOptions, TurnOutcome, TurnPhase, UserConversationStatus, UserConversationSummary,
+    WorkspaceDiff, DEFAULT_MODEL,
+};
+use caos::workspace::{
+    commit_working_tree, fetch_remote_branch_tip, load_conversation_workspace,
+    local_default_branch_tip, prepare_publish_workspace, publish_conversation_pr,
+    publish_merge_target, remote_default_branch,
 };
 use caos::{GitTransport, Transport};
 use ratatui_core::buffer::{Buffer, CellWidth};
@@ -22,12 +28,6 @@ use ratatui_crossterm::crossterm::event::{
 };
 
 use super::args::Args;
-use super::workspace::{
-    commit_working_tree, fetch_remote_branch_tip, load_conversation_workspace,
-    local_default_branch_tip, prepare_publish_workspace, publish_conversation_pr,
-    publish_merge_target, remote_default_branch,
-};
-
 #[path = "ui.rs"]
 pub(crate) mod ui;
 
@@ -39,21 +39,6 @@ fn collapse_whitespace(text: &str) -> String {
     text.split_whitespace().collect::<Vec<_>>().join(" ")
 }
 
-fn automatic_title(prompt: &str) -> String {
-    const MAX_CHARS: usize = 60;
-
-    let title = collapse_whitespace(prompt);
-    if title.chars().count() <= MAX_CHARS {
-        return title;
-    }
-
-    title
-        .chars()
-        .take(MAX_CHARS - 1)
-        .chain(std::iter::once('…'))
-        .collect()
-}
-
 fn message_preview(text: &str, max_cells: u16) -> String {
     let text = collapse_whitespace(text);
     if max_cells == 0 {
@@ -1327,7 +1312,7 @@ impl ConversationState {
 
     fn apply_automatic_title(&mut self, prompt: &str) {
         if !self.automatic_title_fallback_applied {
-            let fallback = automatic_title(prompt);
+            let fallback = automatic_conversation_title(prompt);
             if self.automatic_title {
                 self.title = fallback.clone();
             }
@@ -3771,19 +3756,6 @@ fn screen_point(column: u16, row: u16, area: Rect) -> TranscriptPoint {
     }
 }
 
-fn fresh_conversation_id(t: &GitTransport, user: &str) -> Result<String, String> {
-    let created = std::time::SystemTime::now()
-        .duration_since(std::time::UNIX_EPOCH)
-        .map_err(|error| format!("reading the clock: {error}"))?
-        .as_nanos();
-    let descriptor = format!(
-        "caos conversation\ncreator {user}\ncreated {created}\nprocess {}\n",
-        std::process::id()
-    );
-    t.put_object("blob", descriptor.as_bytes())
-        .map(|id| id.to_string())
-}
-
 fn new_conversation_options(
     mut options: TurnOptions,
     requested_base: Option<String>,
@@ -4279,12 +4251,15 @@ mod tests {
     #[test]
     fn automatic_titles_collapse_whitespace_and_limit_unicode_scalars() {
         assert_eq!(
-            automatic_title("  Review\t the\nλ parser  "),
+            automatic_conversation_title("  Review\t the\nλ parser  "),
             "Review the λ parser"
         );
-        assert_eq!(automatic_title(&"界".repeat(60)), "界".repeat(60));
         assert_eq!(
-            automatic_title(&"界".repeat(61)),
+            automatic_conversation_title(&"界".repeat(60)),
+            "界".repeat(60)
+        );
+        assert_eq!(
+            automatic_conversation_title(&"界".repeat(61)),
             format!("{}…", "界".repeat(59))
         );
     }

crates/caos/src/bin/tui/mod.rs

@@ -21,7 +21,6 @@ use ratatui_crossterm::CrosstermBackend;
 
 mod app;
 mod args;
-mod workspace;
 
 use app::{ui::render, App, MouseAction, View};
 use args::{usage, Args};

crates/caos/src/chat.rs

@@ -1209,7 +1209,8 @@ fn remote_refs(
         .collect())
 }
 
-fn validate_conversation_title(title: &str) -> Result<&str, String> {
+/// Trim and validate a title before a client displays or persists it.
+pub fn normalize_conversation_title(title: &str) -> Result<&str, String> {
     if title.chars().any(char::is_control) {
         return Err("conversation title must contain no control characters".to_string());
     }
@@ -1241,7 +1242,7 @@ fn create_conversation_title_if_absent(
     id: &str,
     title: &str,
 ) -> Result<(), String> {
-    let title = validate_conversation_title(title)?;
+    let title = normalize_conversation_title(title)?;
     let title_ref = conversation_title_ref(id)?;
     if remote_ref(t, &title_ref)?.is_some() {
         return Ok(());
@@ -1345,7 +1346,7 @@ pub fn fork_conversation(
     from: &str,
 ) -> Result<String, String> {
     validate_hash(from, "fork source")?;
-    let title = validate_conversation_title(title)?;
+    let title = normalize_conversation_title(title)?;
     let refname = conversation_ref(id)?;
     let title_ref = conversation_title_ref(id)?;
     let active_ref = user_conversation_ref(user, UserConversationStatus::Active, id)?;
@@ -1384,7 +1385,7 @@ pub fn fork_conversation(
 }
 
 pub fn set_conversation_title(t: &GitTransport, id: &str, title: &str) -> Result<(), String> {
-    let title = validate_conversation_title(title)?;
+    let title = normalize_conversation_title(title)?;
     let hash = t.put_object("blob", title.as_bytes())?.to_string();
     let title_ref = conversation_title_ref(id)?;
     t.git_capture(
@@ -1407,8 +1408,8 @@ pub fn compare_and_set_conversation_title(
     expected: &str,
     title: &str,
 ) -> Result<bool, String> {
-    let expected = validate_conversation_title(expected)?;
-    let title = validate_conversation_title(title)?;
+    let expected = normalize_conversation_title(expected)?;
+    let title = normalize_conversation_title(title)?;
     let expected_hash = t.put_object("blob", expected.as_bytes())?.to_string();
     let candidate = t.put_object("blob", title.as_bytes())?.to_string();
     let title_ref = conversation_title_ref(id)?;
@@ -1615,7 +1616,7 @@ pub fn list_user_conversations(
                 }
                 let title = String::from_utf8(bytes)
                     .map_err(|_| format!("conversation {id:?} title is not UTF-8"))?;
-                validate_conversation_title(&title)?.to_string()
+                normalize_conversation_title(&title)?.to_string()
             } else {
                 id.clone()
             };
@@ -1694,6 +1695,38 @@ pub fn first_available_conversation_name<'a>(names: impl IntoIterator<Item = &'a
     unreachable!("the integer conversation-name space is not finite")
 }
 
+/// Create a presentation-independent id for a conversation before its first
+/// durable event exists.
+pub fn fresh_conversation_id(t: &GitTransport, user: &str) -> Result<String, String> {
+    let created = std::time::SystemTime::now()
+        .duration_since(std::time::UNIX_EPOCH)
+        .map_err(|error| format!("reading the clock: {error}"))?
+        .as_nanos();
+    let descriptor = format!(
+        "caos conversation\ncreator {user}\ncreated {created}\nprocess {}\n",
+        std::process::id()
+    );
+    t.put_object("blob", descriptor.as_bytes())
+        .map(|id| id.to_string())
+}
+
+/// Derive the immediate fallback title shown while best-effort title
+/// generation is still running.
+pub fn automatic_conversation_title(prompt: &str) -> String {
+    const MAX_CHARS: usize = 60;
+
+    let title = prompt.split_whitespace().collect::<Vec<_>>().join(" ");
+    if title.chars().count() <= MAX_CHARS {
+        return title;
+    }
+
+    title
+        .chars()
+        .take(MAX_CHARS - 1)
+        .chain(std::iter::once('…'))
+        .collect()
+}
+
 fn value_text(value: &Value) -> String {
     value
         .as_str()
@@ -2096,7 +2129,7 @@ fn parse_generated_title(text: &str) -> Result<String, String> {
     if title.chars().count() > 60 {
         return Err("conversation title result exceeds 60 characters".to_string());
     }
-    validate_conversation_title(&title).map(str::to_string)
+    normalize_conversation_title(&title).map(str::to_string)
 }
 
 pub fn describe_tool_set(
@@ -3115,17 +3148,7 @@ fn waterfall_string(value: &Value, key: &str, target: &mut Option<String>) -> Re
 }
 
 fn default_title(message: &str) -> String {
-    const MAX_CHARS: usize = 60;
-    let compact = message.split_whitespace().collect::<Vec<_>>().join(" ");
-    if compact.chars().count() <= MAX_CHARS {
-        compact
-    } else {
-        compact
-            .chars()
-            .take(MAX_CHARS - 1)
-            .chain(std::iter::once('…'))
-            .collect()
-    }
+    automatic_conversation_title(message)
 }
 
 // ---------------------------------------------------------------------------
@@ -3673,7 +3696,7 @@ mod tests {
     #[test]
     fn canonical_titles_reject_controls() {
         assert_eq!(
-            validate_conversation_title("  useful title  ").unwrap(),
+            normalize_conversation_title("  useful title  ").unwrap(),
             "useful title"
         );
         for title in [
@@ -3683,11 +3706,11 @@ mod tests {
             "nul\0byte",
         ] {
             assert!(
-                validate_conversation_title(title).is_err(),
+                normalize_conversation_title(title).is_err(),
                 "accepted {title:?}"
             );
         }
-        assert!(validate_conversation_title("   ").is_err());
+        assert!(normalize_conversation_title("   ").is_err());
     }
 
     #[test]

crates/caos/src/lib.rs

@@ -40,6 +40,8 @@ use gix::objs::WriteTo;
 pub mod chat;
 pub use chat::{cli_chat, cli_talk};
 
+pub mod workspace;
+
 mod eval;
 pub use eval::cli_eval_path;
 

crates/caos/src/bin/tui/workspace.rs → crates/caos/src/workspace.rs

@@ -3,19 +3,19 @@ use std::path::Path;
 use std::process::{Command, Output, Stdio};
 
 #[derive(Clone, Debug, PartialEq, Eq)]
-pub(crate) struct PreparedPublishWorkspace {
-    pub(crate) head: String,
-    pub(crate) tree: String,
+pub struct PreparedPublishWorkspace {
+    head: String,
+    tree: String,
 }
 
 /// Check out a conversation's head commit in the local working tree.
 ///
 /// This is deliberately client policy rather than part of the chat engine:
-/// the TUI chooses when to mutate the checkout and requires confirmation before
+/// clients choose when to mutate the checkout and require confirmation before
 /// calling it. Rather than applying the base-to-head diff as unstaged changes,
 /// this moves the local HEAD onto the conversation head commit so the checkout
 /// exactly matches it.
-pub(crate) fn load_conversation_workspace(head: &str, cwd: &Path) -> Result<(), String> {
+pub fn load_conversation_workspace(head: &str, cwd: &Path) -> Result<(), String> {
     let dirty = capture_required(
         "git",
         &["status", "--porcelain=v1", "--untracked-files=all"],
@@ -43,7 +43,7 @@ pub(crate) fn load_conversation_workspace(head: &str, cwd: &Path) -> Result<(),
 /// committed the changes themselves), nothing is committed and the current
 /// `HEAD` is returned. `git add -A` respects `.gitignore`, so the commit
 /// mirrors what a normal commit of the working tree would contain.
-pub(crate) fn commit_working_tree(message: &str, cwd: &Path) -> Result<String, String> {
+pub fn commit_working_tree(message: &str, cwd: &Path) -> Result<String, String> {
     capture_required("git", &["add", "-A"], cwd)?;
     // `git diff --cached --quiet` exits non-zero exactly when the index differs
     // from HEAD, i.e. there is something to commit.
@@ -59,7 +59,7 @@ pub(crate) fn commit_working_tree(message: &str, cwd: &Path) -> Result<String, S
 /// Name the exact commit the ordinary publish turn must merge. A stacked
 /// snapshot keeps the selected base's tree but shares the conversation's base,
 /// so `merge` applies only this conversation's delta.
-pub(crate) fn publish_merge_target(
+pub fn publish_merge_target(
     conversation_base: &str,
     publish_base: &str,
     stacked: bool,
@@ -87,7 +87,7 @@ pub(crate) fn publish_merge_target(
     )
 }
 
-pub(crate) fn prepare_publish_workspace(
+pub fn prepare_publish_workspace(
     head: &str,
     target: &str,
     cwd: &Path,
@@ -175,7 +175,7 @@ pub(crate) fn prepare_publish_workspace(
 ///
 /// The chat core has already merged, resolved, tested, and removed harness
 /// state. Keep only that tree as one commit above the exact fetched PR base.
-pub(crate) fn publish_conversation_pr(
+pub fn publish_conversation_pr(
     name: &str,
     workspace: &PreparedPublishWorkspace,
     pr_base: &str,
@@ -240,7 +240,7 @@ pub(crate) fn publish_conversation_pr(
 /// fetch`, so it stays instant (e.g. on every Ctrl+N) instead of blocking on
 /// round-trips to `origin`. Publishing a PR still fetches, where a fresh remote
 /// tip matters.
-pub(crate) fn local_default_branch_tip(cwd: &Path) -> Result<(String, String), String> {
+pub fn local_default_branch_tip(cwd: &Path) -> Result<(String, String), String> {
     // `refs/remotes/origin/HEAD` is the local symref recording origin's default
     // branch; it is set at clone time and refreshed by `git remote set-head`.
     let head_ref = capture_required("git", &["symbolic-ref", "refs/remotes/origin/HEAD"], cwd)
@@ -260,7 +260,7 @@ pub(crate) fn local_default_branch_tip(cwd: &Path) -> Result<(String, String), S
     Ok((branch, commit))
 }
 
-pub(crate) fn remote_default_branch(cwd: &Path) -> Result<String, String> {
+pub fn remote_default_branch(cwd: &Path) -> Result<String, String> {
     let output = command_output("git", &["ls-remote", "--symref", "origin", "HEAD"], cwd)?;
     let stdout = require_success("git", output)?;
     parse_remote_default_branch(&String::from_utf8_lossy(&stdout))
@@ -287,7 +287,7 @@ fn parse_remote_default_branch(output: &str) -> Result<String, String> {
     Err("origin HEAD did not advertise a default branch".to_string())
 }
 
-pub(crate) fn fetch_remote_branch_tip(branch: &str, cwd: &Path) -> Result<String, String> {
+pub fn fetch_remote_branch_tip(branch: &str, cwd: &Path) -> Result<String, String> {
     let remote_ref = format!("refs/heads/{branch}");
     let tracking_ref = format!("refs/remotes/origin/{branch}");
     let refspec = format!("+{remote_ref}:{tracking_ref}");